The present invention relates to the field of electrical assembly installations for pipe wirings and, more particularly, for connecting metal cable pipes or conduits for installation in buildings and other types of construction.
The technical problem solved by the present invention is a new pipe connector providing:
threadless connection of metal pipes or conduit sections; PA1 radial assembly; PA1 possibility of assembly in hard-to-reach places with the limited place for installation tools; PA1 assembly simplicity; PA1 reliable electric contacts between the connecting pipes; PA1 reliable moisture and dust-proof seal at the junction. PA1 1) instead of a complicated conic-flange joint, the pipes are held due to their close compression between half-couplings that is achieved by large forces created when tightening together the half-coupling flanges, particularly when making half-couplings in the form of incomplete cylinders to place the flanges under tension when fully seated; PA1 2) the problem of lateral packing is solved by the special form of joined lateral faces of half-couplings particularly when making them in such a way that when assembling, the necks and beads fit into another with tension; in this case, if half-couplings are made split (sectioned) the same necks and beads keep the half-couplings from axially shifting; PA1 3) metal split rings solve the problem of the end packing, in this case unlike the known packing, the rings are held down not due to the axial force of the coupling nut (see the above mentioned O-Z catalog page 80 and page 96) but due to the radial force resulting from the tightened flanges and radial groove of conic form on the internal surface of the half-couplings; PA1 4) the construction provides both axial and radial assembly which greatly simplifies the assembly and installation especially in hard-to-reach places and when the place for tools is limited and when automatic alignment of the connected pipes is desired; PA1 5) the construction enables the assembly process to be optimized.
The basic prior art design of known connectors is a cylindrical coupling with internal thread into which connected pipes are either screwed in from both sides or the coupling itself is preliminary fully screwed on one of the pipes and then the second pipe is screwed on to the other half of the connector. See O-Z Gidney Product Catalog 8700--Electrical Fittings and Enclosure 1987, Page 66, "ICC TYPE". The required presence of the thread on this prior art pipe junction greatly complicates the assembly and limits application of such connectors in electrical assembly installations.
A prior art improvement includes smooth, unthreaded connectors, for example, the coupling comprising a shaped shackle having openings for the connected pipes and threaded holes to receive coupling bolts, which when screwed, causes the shackle ends to engage the pipes and couple them together. See USSR Patent No. 1,350,728. In spite of technological simplicity of production, such coupling does not provide sufficient mechanical strength as well as moisture and dust prevention of the junction for most applications.
There are known further couplings for threadless pipes connection, for example, where the pipe coupling action is carried out with the help of lock screws. See the above mentioned Product Catalog, Page 81, "29" type and Page 97, "5000" type or Japan Published Patent Application No. 61-43929. Additionally, said Japanese Publication includes an elastic plate having a semi-ring form is installed in the coupling held to the pipe by the lock screw to create a closed or sealed connection. The main disadvantage of such standard connectors lies in the fact that it is practically impossible to provide good electric contact, moisture and dust impenetrability and assembly simplicity simultaneously because, on the one hand, it is necessary to have as small clearance between the coupling and the pipe as possible and on the other hand this clearance must be as big as possible, otherwise, in case of the slightest warp or axes shift of the connected pipes, it will be impossible to install them in the cylindrical coupling.
More complicated connector constructions are known comprising a cylindrical coupling with two-way external thread, two coupling nuts, and split sealing rings. See the above mentioned O-Z Catalog, page 80 "30" type; page 96 "6000S" and "6000RS" types. Connected pipes are inserted from both sides into the coupling whereupon the nuts, preliminary mounted on pipes, are screwed on it. When screwing, the nut holds down the sealing ring close to the pipe, providing good electric contact and high moisture impenetrability. The given connector provides also high mechanical strength to the joint. However, the characteristics of the axial assembly of this connector involve causes assembly difficulties in cases of axial warp of the pipes and in hard-to-reach places, particularly when one connector half is already on an installed pipe and a tightening tool is required to be used.
It should be mentioned that radial assembly is not used for the most simplest to make joints because the problem of the end packing is compounded by the problem of the lateral packing. To avoid such a problem, half-coupling joints have been used. See, for example Japan Published Patent Application No. 64-4404. The joint provides good mechanical strength and assembly simplicity but does not protect the joint from the environment.
Another prior art pipe connector comprises flanges in the form of conic disks fixed (usually welded) near the ends of the connected pipes and two half-couplings having tightened flanges along the lateral faces and an internal radial conical groove. See Orlov P. E. "Desdign base: Methodical catalog" Two volumes, volume #2 by Uchaev P.E. 3rd corrected publishing, Sect. "M" Mechanical engineering, 1988. Page 544 (prototype-page 210, picture-drawing 494- VI). During assembly, the surfaces of the radial groove of the tightened half-couplings act upon the conical surfaces of pipe flanges, thus tightening the pipes together. The connector also has a sealing ring installed between the tightened flanges of half-couplings which purportedly solves the problem of lateral packing. There is no serious problem with the end packing for this connector because conic flanges are installed on pipes permanently (not sectionally). The main disadvantage of this connector is the assembly complexity because conic flanges need to be welded on the device during assembly and with rather high precision.